A main objective of the study was to determine the amount of aerosol surface area, particularly that of black carbon aerosol (BCA), available for reaction with stratospheric constituents and to assess, if possible, the importance of these reactions. The AWI collect aerosol and BCA particles on thin palladium wires that are exposed to the ambient air in a controlled manner. The samples are returned to the laboratory for subsequent analysis. The product of the AWI analysis is the size, surface area, and volume distributions, and the morphology and elemental composition of the aerosols and BCA. Modifications to the AWI data analysis procedures were required i n which the collection of BCA is modeled as a fractal aggregate. The new analysis results in an increase in BCA surface area of approximately 24 and an increase in mass of 10 from the previous method. The character of the BCA and its area distributions measured during POLARIS are compared with those made by the AWI on past missions; the comparisons show trends in the spatial and temporal distribution.